SAN DIEGO  The man at the center of a ricin scare at a Las Vegas motel says he never had any intention of hurting anyone with the deadly biological agent, his brother told The Associated Press.

Roger Bergendorff, who finally regained consciousness last week after almost a month of hospitalization, possessed the ricin powder found in his motel room in February and believes he was contaminated by it, said Erich Bergendorff, who talked to his brother on the phone Sunday.

"He just confirmed that it was not intended for anybody," Erich Bergendorff said in a telephone interview from his home north of San Diego in Escondido. "It was something that would be used for his own purposes, for self-defense."

Erich Bergendorff said his brother was cooperating with investigators who questioned him at the hospital Friday. Las Vegas police referred questions to the FBI, which declined to comment Monday.

Erich Bergendorff said Sunday's conversation was his first with Roger since he regained consciousness. He said his brother told him the ricin powder was easy to make but wasn't clear on whether he or someone else made it.

"He did talk as though he just had it there; he was almost kind of casual about it," Erich Bergendorff said. "... He did mention the ricin and seemed to say something like, 'Gee, it sure worked on me.'"

Ricin can be lethal in amounts the size of the head of a pin. It has no antidote and is legal only for cancer research.

In court documents, police said "a large quantity" of ricin was in vials found in Roger Bergendorff's hotel room. He summoned an ambulance Feb. 14, complaining of respiratory distress, but the ricin wasn't discovered until a cousin went to the hotel to pick up his belongings two weeks later.

Police say they also found firearms in the room, along with castor beans -- from which ricin is derived -- and four "anarchists cookbooks" in the room, marked at sections describing how to make ricin. But officials have said they have not found evidence in the motel room or elsewhere of contamination and have downplayed the possibility that Roger Bergendorff posed a threat.

Authorities have refused to say whether they plan to charge Roger Bergendorff, who had been suffering from respiratory ailments and failing kidneys.

Experts have said his symptoms appeared consistent with ricin exposure, but the poison breaks down in the body within days, making it hard to trace.

Ricin is categorized as a biological agent under the Biological Weapons Anti-Terrorism Act of 1989, which provides for the possibility of life in prison and unspecified fines for production, acquisition or possession of a biological agent, according to Dean Boyd, a spokesman for the Justice Department.

Mere possession for purposes other than "bona fide research" or "other peaceful purpose" carries the possibility of fines and up to 10 years in federal prison, Boyd said.

Nevada state law makes manufacturing or possessing a biological weapon or toxin a felony punishable by up to 10 years to life in state prison.

Friends and family members described Bergendorff, an illustrator, as a loner who struggled to pay his bills while moving around California, Nevada and Utah with his beloved dog and cats.

He had lived in recent months at the Extended Stay America motel several blocks off the Las Vegas Strip while waiting for a freelance job contract.

Erich Bergendorff said his brother was deeply saddened by the death of their older brother in January but insisted Roger Bergendorff had not been suicidal.

"He did say he felt very empty with his loss," said Erich Bergendorff. He added that his brother was lonely in the hospital and newly distraught after learning that his dog was euthanized after the Humane Society found her starving and without water in his motel room.

The Extended Stay America hotel is shown in Las Vegas in this Thursday, March 6, 2008 file photo. A man who may be able to unlock the mystery of how a large quantity of highly toxic ricin came to be in his motel room at the Extended Stay America has regained consciousness and was being questioned by investigators, authorities said Friday, March 14, 2008. (AP Photo/Jae C. Hong)